<template>
	<view>
		<view class="scroll-view-container">
			<!-- 左侧的滚动视图区域 -->
			<scroll-view class="left-scroll-view" scroll-y>
				<block v-for="(item, i) in cateList" :key="i">
					<view :class="['left-scroll-view-item', i === active ? 'active' : '']" @click="activeChanged(i)">
						{{item.cat_name}}
					</view>
				</block>
			</scroll-view>
			<!-- 右侧的滚动视图区域 -->
			<scroll-view class="right-scroll-view" scroll-y :scroll-top="scroll">
				<!-- 二级列表的展示 -->
				<view class="cate-lv2" v-for="(item2 , i2 ) in cateLevel2" :key="i2">
					<view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
					<!-- 动态渲染三级分类的列表数据 -->
					<view class="cate-lv3-list">
						<!-- 三级分类 Item 项 -->
						<view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
							<!-- 图片 -->
							<image :src="item3.cat_icon"></image>
							<!-- 文本 -->
							<text>{{item3.cat_name}}</text>
						</view>
					</view>
				</view>

			</scroll-view>
		</view>
	</view>
</template>

<script>
	import {
		getCateList
	} from 'api/cate.js'
	export default {
		data() {
			return {
				cateList: [],
				active: 0,
				// 二级分类列表
				cateLevel2: [],
				// 滚动条的距离
				scroll: 0


			};
		},
		onLoad() {
			this.getCateList()
		},

		methods: {
			async getCateList() {
				const res = await getCateList()
				this.cateList = res
				// 
				this.cateLevel2 = res[0].children
			},
			// 选中项改变的事件处理函数
			activeChanged(i) {
				this.active = i
				this.cateLevel2 = this.cateList[i].children
				// 取巧的方式，使滚动条的距离回到顶部
				this.scroll = this.scroll === 0 ? 1 : 0
			},
			// 点击三级分类项跳转到商品列表页面
			gotoGoodsList(item3) {
			  uni.navigateTo({
			    url: '/skylub/goods_list/goods_list?cid=' + item3.cat_id
			  })
			}
		}
	}
</script>

<style lang="scss">
	.scroll-view-container {
		display: flex;
		height: 100vh;

		.left-scroll-view {
			width: 120px;

			.left-scroll-view-item {
				line-height: 60px;
				background-color: #f7f7f7;
				text-align: center;
				font-size: 12px;

				// 激活项的样式
				&.active {
					background-color: #ffffff;
					position: relative;

					// 渲染激活项左侧的红色指示边线
					&::before {
						content: ' ';
						display: block;
						width: 3px;
						height: 30px;
						background-color: #c00000;
						position: absolute;
						left: 0;
						top: 50%;
						transform: translateY(-50%);
					}
				}
			}
		}

		.cate-lv2-title {
			font-size: 12px;
			font-weight: bold;
			text-align: center;
			padding: 15px 0;
		}

		.cate-lv3-list {
			display: flex;
			flex-wrap: wrap;

			.cate-lv3-item {
				width: 33.33%;
				display: flex;
				flex-direction: column;
				justify-content: center;
				align-items: center;
				margin-bottom: 10px;

				image {
					width: 66px;
					height: 66px;
				}

				text {
					font-size: 12px;
				}
			}

		}
	}
</style>
